1. Field of the Invention
This invention relates to the field of exercise equipment. More particularly, this invention relates to the field of an adjustable, astable seat for increasing the use of a user's core muscles while exercising.
2. Description of Related Art
Numerous abdominal exercise devices have been proposed and/or sold. A device called the Ab Doer Twist® and generally shown in U.S. Design Pat. No. D639,873, owned by the assignee of the present application, includes a chair and a handlebar type device attached to a flexing, torsional rod, for use in exercising the abdominal muscles. Other abdominal exercise machines or devices are disclosed variously in U.S. Pat. No. 9,168,416 to Ho et al.; U.S. Pat. No. 9,005,089 to Huang; U.S. Pat. No. 8,986,179 to Cares; and U.S. Pat. No. 8,226,533 to Wessels et al.
Additionally, various inflated seating devices variously called stability disks are used to increase a user's core muscles while sitting.